{
  "event": "thank_you",
  "event_parameters": [
    {
      "name": "source_event",
      "note": "The existing event the new event is built from. Here: page_view.",
      "required": true,
      "type": "string"
    },
    {
      "name": "matching_condition",
      "note": "The condition the source event must meet. Here: page_location contains /thank-you.",
      "required": true,
      "type": "string"
    },
    {
      "name": "parameter_configuration",
      "note": "On by default: the new event carries over the source event's parameters.",
      "required": false,
      "type": "string"
    }
  ],
  "rules": [
    "You can create up to 50 events in a property with the Create event feature.",
    "A created event is not retroactive: it only applies to data collected after creation.",
    "The source event must already be collected; you cannot create an event from one GA4 has never seen.",
    "Parameters in the items array cannot be used to define a new event.",
    "It can take up to 1 hour before a created event starts to show in GA4.",
    "Creating an event copies the existing event; the original keeps collecting unchanged.",
    "A created event appears in the Custom events table immediately, but not in the Recent events tab until Analytics processes the event."
  ],
  "source": "Analytics Help \u2014 Create or modify key events (support.google.com/analytics/answer/12844695), opened 11 November 2026",
  "verified_example": {
    "arithmetic_check": {
      "checked_with": "Python 3.12.3, run 11 November 2026",
      "computation": "50 - 12",
      "matches_limit_field": true,
      "result": 38
    },
    "event": "thank_you",
    "limit": {
      "created_events_max": 50,
      "created_events_remaining": 38,
      "created_events_used": 12
    },
    "matching_condition": {
      "operator": "contains",
      "parameter": "page_location",
      "value": "/thank-you"
    },
    "source": "Google's worked example in the Create or modify key events help page: thank_you created from page_view",
    "source_event": "page_view"
  }
}